When working in areas where there is known to be, or there is a potential of there being, dusts, fumes, gases or other contaminants that are potentially hazardous or harmful to health, it is usual for a worker to use a respirator or a clean air supply source. While a large variety of respiratory devices are available, some commonly used devices include powered air purifying respirators (PAPR) and a self-contained breathing apparatus (SCBA). A PAPR typically includes a blower system comprising a fan powered by an electric motor for delivering a forced flow of air through a tube to a head top worn by a user. A PAPR typically includes a device (i.e., turbo) that draws ambient air through a filter, forces the air through a breathing tube and into a helmet or head top to provide filtered air to a user's breathing zone, around their nose or mouth. An SCBA provides clean air from a compressed air tank through a tube or hose to the interior of a head top worn by a user. In order for a user to benefit from a clean air supply source, it is important for the user to have a seal around the exterior of a head top or helmet worn by the user.